The invention relates to a gearbox arrangement which comprises a first gearbox with an adjoining range gearbox.
The first gearbox is with advantage a dual-clutch gearbox. A dual-clutch gearbox comprises a first set of components substantially corresponding to the components in a first mechanical gearbox, and a second set of components substantially corresponding to the components in a second mechanical gearbox. The first set of components cover all the odd-numbered gears in the dual-clutch gearbox and the second set of components cover all the even-numbered gears. Switching between the two sets of components involves using clutch devices which make it possible to engage and disengage the respective sets of components. The fact that the two sets of components are used alternately makes it possible to effect stepped upward and downward gear changes in a dual-clutch gearbox without torque interrupt.
Many heavy vehicles often have a first gearbox connected by a first motion-transmitting connection to a so-called range gearbox. A range gearbox usually comprises a planetary gear which can provide each primary gear in the first gearbox with respective high and low transmission ratios. To operate the range gearbox, a driver can move an operating means, which may be fastened around a gear lever in the driving cab, to a position which indicates a desired gear position of the range gearbox. The driver moving the operating means to a desired position usually results in activation of an operating cylinder which is controlled by compressed air and which moves a ring gear of the range gearbox between the respective high and low transmission ratio positions. Alternatively, the gear change may be indicated by an automatic system. As the ring gear is connected in the low transmission ratio position to a stationary clutch cone and in the high transmission ratio position to a clutch cone on a rotating shaft, there has to be a torque interrupt during a gear change process in the range gearbox in order to synchronise the speed of the ring gear before it can be moved between the two positions.